Toxicity of high-activity 111In-Octreotide therapy in patients with disseminated neuroendocrine tumours.

Disseminated neuroendocrine tumours are difficult to treat and are generally not responsive to radiotherapy or chemotherapy. Nuclear medicine techniques using a radiolabelled somatostatin analogue, 111In-Octreotide, have been used for the diagnosis of neuroendocrine tumours. It has been suggested that high activities of such an agent may have a therapeutic effect. The aims of this study were to assess toxicity and to determine if there had been evidence of efficacy. Eight patients with known disseminated neuroendocrine tumours were enrolled in the study; six had carcinoid tumours, one had a medullary cell carcinoma of the thyroid and one patient had a malignant gastrinoma. Between 1.3 and 4.6 GBq of 111In-Octreotide were administered to each patient for up to five administrations over 12 months. A total of 23 administrations were given. Tests of vital signs, renal, liver and endocrine function as well as haematological markers were taken before and after treatment. The treatment was well tolerated with only one patient suffering from a sensation of flushing during the infusion but no changes in vital sings. There was a transient (up to 48 h) drop in circulating lymphocytes in four patients and platelets in two patients; no supportive therapy was needed. One patient with severe renal impairment had a slight reduction in glomerular filtration rate. We conclude that high-activity 111In-Octreotide is well tolerated with low toxicity and can be considered for use in patients with disseminated neuroendocrine tumours. Further work is now being performed to assess efficacy.

Comparison of functional imaging and standard CT in evaluation of disease extent in patients with tumours showing neuroendocrine features.

BACKGROUND: The diagnostic approach that should be used in disseminated neuroendocrine tumours (NET) remains a significant clinical problem. A novel approach has been the use of 111In Octreotide as functional imaging to find NETs. Therefore, the aim of this retrospective study is to report our comparison with direct CT as standard anatomical imaging. MATERIAL AND METHODS: A total of 48 patients (aged 16-79 years; mean age 55, SD 14 years) were imaged using both techniques with final histological confirmation of NET. Histology was as follows: 26 carcinoids; 2 pheochromocytomas; 4 gastrinomas, 1 islet tumour; 2 paragangliomas, 1 modullary carcinoma of the thyroid, 8 undetermined NET and 4 other tumours with signs of neuro-ectodermal cancers (2 hepatocellular carcinomas (HCC), fibrolamellar HCC and fibrous tumour). All patients had (111)In Octreotide and 30 had (123)I mIBG scans followed by spiral CT with contrast enhancement. 26 patients had single functional scans and 22 had multiple, up to 6 scans. Extent of disease as number of lesions was compared between CT and octreotide. RESULTS: CT was the best modality in 11 patients, in 6 it was as good as (111)In Octreotide. mIBG was the best in 6 patients; in 3 patients mIBG was as good as octreotide study. In 22 patients (111)In Octreotide was the most effective modality. In one patient there was no advantage with any of the tests. Comparison of the number of organs involved indicated that an octreotide study was much more effective than CT scanning (Wilcoxon matched pairs test, p < 0.001) and also the overall number of lesions detected using (111)In Octreotide was greater than with CT (Wilcoxon Matched Pairs test p < 0.01). CONCLUSION: Our results confirm the recommendation of the European NET group that functional imaging should be performed in patients with suspected NET.

[Evaluation of the relationship between chosen factors and results of whole body scintigraphy with 131I in patients with differentiated thyroid cancers]. / Ocena zaleznosci wybranych czynników i wyników badan scyntygraficznych calego ciala za pomoca 131I u chorych ze zróznicowanymi rakami tarczycy.

Treatment and diagnostics with 131I play an important role in patients with differentiated thyroid cancer (DTC) after thyreoidectomy. The aim of the study was to assess the influence of some factors on ablative therapy results. Fifty seven patients with DTC were investigated (44 females--mean age 46.6 yrs, 13 males--mean age 55.6 yrs.). Papillary thyroid cancer was diagnosed in forty five patients (79%) however, follicular thyroid cancer in the others (21%). We performed post-therapeutic whole-body scan (WBS) after high fixed doses of 131I (median = 75 mCi) and six months later diagnostic WBS (mean 4.3 mCi) in every patient. Postoperative radioiodine uptake, levels of TSH and thyroglobulin (Tg) serum concentrations were assessed after thyroid hormones withdrawal before imaging. The absence of radioiodine uptake in the thyroid bed (effective ablation) was observed in 64.9% of patients. In other cases scans showed significantly diminished uptake of the tracer in the remnants. Statistically significant difference in TSH levels before and after radioiodine therapy (75.6 vs. 106.7 microIU/ml, p < 0.001) was found in all patients. However, effectiveness of the ablative therapy did not depend on radioiodine uptake, TSH and Tg levels before radioiodine treatment.